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Orf in South Africa: Endemic but neglected
2012
Alessandra Scagliarini | Silvia Piovesana | Filippo Turrini | Federica Savini | Fortune Sithole | Cheryl M. McCrindle
A survey amongst sheep and goat producers and veterinarians was undertaken to collect epidemiological data on orf in South Africa. Previous epidemiological studies on the presence of the disease in the country have not been documented and this report is the first descriptive epidemiological study of orf in South Africa. A seven-month investigation, realised by direct and indirect interviews and field observation, enabled us to outline incidence and risk factors of this disease and to better understand how the local farmers in rural areas relate to it. The results may contribute to better management of the disease in rural areas. By means of molecular analyses the phylogenetic relationships between field isolates from different areas have been identified. The findings gave a first important contribution to the general assessment of the economic impact of orf virus infections and the extent of the risk to human health.
显示更多 [+] 显示较少 [-]Descriptions of strigea cercariae from the Gauteng and North West Provinces, South Africa
2012
Esmey B.E. Moema | Pieter H. King | Chantelle Baker
Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, <em>Lymnaea natalensis</em>, Krauss 1848 and <em>Bulinus tropicus</em>, Krauss 1848 were sampled from five localities in Gauteng and one locality in the North West Province from 2007 to 2010. These snails were collected in order to study their cercarial sheddings. They were found to be infected with three different types of strigea cercariae, of which the morphology was studied using standard light and scanning electron microscopy techniques.
显示更多 [+] 显示较少 [-]Impact of HIV and AIDS on food security in Rufiji District, Tanzania
2012
Kim A. Kayunze
Relatively high prevalence of HIV and AIDS and food insecurity in Rufiji District whilst the linkage between the two problems was not known was the basis of this study. Data were collected amongst 225 households between November 2005 and October 2006 through participatory rural appraisal (PRA), household income and expenditure survey (HIES) and structured interviews. Binary logistic regression was used for analysis in which case the dependent variable was food security in terms of food insecure (0) and food secure (1) based on kilocalories consumed per adult equivalent per day. The independent variables included having been affected by HIV and AIDS in terms of not affected (0) and affected (1). The results reveal that the odds for households affected by HIV and AIDS to be food secure were 0.705 times as high as the odds for households not affected by HIV and AIDS to be food secure. This means that households affected by HIV and AIDS were less likely to be food secure as opposed to those not affected by HIV and AIDS. The B statistic for having been affected by HIV and AIDS was negative (B = -0.350) meaning that being affected by HIV and AIDS had negative impact on food security. However, the Wald statistic which shows the magnitude of impact was small (0.251) and not significant (p = 0.617). This shows that HIV and AIDS had little impact on food security. Based on these findings, it is concluded that although being affected by HIV and AIDS has negative impact on food security, it does not automatically make households food insecure, especially in a short run, and that some non-HIV and AIDS factors like high dependency ratio and low ability to buy food have bigger negative impact than that of HIV and AIDS on food security. On the basis of the conclusion, it is recommended that efforts to improve food security amongst households affected by HIV and AIDS should consider both HIV and AIDS and non-HIV and AIDS factors.
显示更多 [+] 显示较少 [-]Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania
2012
Epaphras A. Muse | Esron D. Karimuribo | George C. Gitao | Gerald Misinzo | Lesakit S.B. Mellau | Peter L.M. Msoffe | Emmanuel S. Swai | Mbyuzi O. Albano
A study was carried out to confirm and identify sources and elucidate factors associated with the introduction of Peste des Petits Ruminants (PPR) in southern Tanzania. This study was conducted in Tandahimba and Newala districts of Mtwara region following suspected outbreak of PPR in the area. Qualitative data were collected using semi-structured questionnaires and in-depth interviews of key informants who included goat and sheep owners with suspected cases of PPR and animal health service providers as well as local administrative authority. Additionally, 216 serum samples and 28 swabs were collected for serological and virological laboratory disease confirmation. The results show that PPR was first introduced in Likuna village of Newala district in February 2009 through newly purchased goats from the Pugu livestock market located about 700 km in the outskirts of Dar es Salaam city. Factors which contributed to spread of PPR included communal grazing and the cheap prices of sick animals bought by livestock keepers for slaughtering in other villages. Laboratory findings confirmed presence of PPR in the area by RT-PCR and serological analysis revealed that seroprevalence was 31%. These findings have confirmed, for the first time, introduction of PPR in southern Tanzania. The presence of PPR poses high risk of southward spread of the disease to other southern African countries in the SADC region thus calling for concerted and collaborative efforts in prevention and control of the disease to avoid losses. Further elaborate studies on the spread, prevalence and risk factors associated with the disease should urgently be investigated.
显示更多 [+] 显示较少 [-]Determination of the seroprevalence of Newcastle disease virus (avian paramyxovirus type 1) in Zambian backyard chicken flocks
2012
Chimuka Musako | Celia Abolnik
A cross-sectional study was conducted in five provinces and 11 districts of Zambia to determine the seroprevalence of Newcastle disease in Zambian backyard chicken flocks. Of the chickens sampled, 73.9% tested positive for avian paramyxovirus type 1 antibodies by means of an enzyme-linked immunosorbent assay. Seroprevalence varied amongst the five provinces sampled, ranging from 82.6% in the Eastern Province to 48.3% in Luapula Province. Seroprevalence also varied amongst the 11 districts sampled, ranging from 91.3% in Monze district of Southern Province to 22.8% in Mufulira district of the Copperbelt province. Overall, the seroprevalence of Newcastle disease in Zambian backyard chicken flocks has increased since the previous study conducted in 1994.
显示更多 [+] 显示较少 [-]Electronic Integrated Disease Surveillance System and Pathogen Asset Control System
2012
Tom G. Wahl | Aleksey V. Burdakov | Andrey O. Oukharov | Azamat K. Zhilokov
Electronic Integrated Disease Surveillance System (EIDSS) has been used to strengthen and support monitoring and prevention of dangerous diseases within One Health concept by integrating veterinary and human surveillance, passive and active approaches, case-based records including disease-specific clinical data based on standardised case definitions and aggregated data, laboratory data including sample tracking linked to each case and event with test results and epidemiological investigations. Information was collected and shared in secure way by different means: through the distributed nodes which are continuously synchronised amongst each other, through the web service, through the handheld devices. Electronic Integrated Disease Surveillance System provided near real time information flow that has been then disseminated to the appropriate organisations in a timely manner. It has been used for comprehensive analysis and visualisation capabilities including real time mapping of case events as these unfold enhancing decision making. Electronic Integrated Disease Surveillance System facilitated countries to comply with the IHR 2005 requirements through a data transfer module reporting diseases electronically to the World Health Organisation (WHO) data center as well as establish authorised data exchange with other electronic system using Open Architecture approach. Pathogen Asset Control System (PACS) has been used for accounting, management and control of biological agent stocks. Information on samples and strains of any kind throughout their entire lifecycle has been tracked in a comprehensive and flexible solution PACS. Both systems have been used in a combination and individually. Electronic Integrated Disease Surveillance System and PACS are currently deployed in the Republics of Kazakhstan, Georgia and Azerbaijan as a part of the Cooperative Biological Engagement Program (CBEP) sponsored by the US Defense Threat Reduction Agency (DTRA).
显示更多 [+] 显示较少 [-]Prevalence of bovine trypanosomosis and its vectors in two districts of East Wollega Zone, Ethiopia
2012
Wagari Tafese | Achenef Melaku | Tewodros Fentahun
Trypanosomosis is a parasitic disease that causes serious economic losses in livestock, especially in sub-Saharan countries. This study was conducted from October 2010 to March 2011 in the Diga and Sasiga districts of the East Wollega zone in western Ethiopia to determine the prevalence of bovine trypanosomosis and its vectors. A total of 386 blood samples were collected from randomly selected animals. Packed cell volume (PCV) was determined and samples were examined for the presence of trypanosomes using the buffy coat technique. Out of 386 blood samples, 8.55% tested positive for trypanosomes. The majority of the infections were caused by Trypanosoma congolense (72.73%), followed by Trypanosoma vivax (27.27%). There were no statistically significant differences (p > 0.05) between districts, altitudes, sexes and ages, but the prevalence was significantly higher (p < 0.05) in cattle which were in poor body condition. The mean PCV value of infected animals (21.45 ± 3.62 s.d.) was significantly lower (p < 0.05) than that of non-infected animals (26.60 ± 4.60 s.d.). A total of 1151 flies were caught by deploying 21 monoconical shaped traps. Of these flies, 822 (71.42%) were Glossina, whilst the remaining flies were either Stomoxys (17.20%) or Tabanus (11.38%). The overall apparent densities of tsetse and biting flies were 1.45 and 0.58 flies per trap per day, respectively. In conclusion, this study confirmed that trypanosomes and their vectors are prevalent and still pose a threat to cattle production in the area. Therefore, proper strategies have to be designed and implemented to minimise their effect on livestock production.
显示更多 [+] 显示较少 [-]From ‘two medicines’ to ‘One Health’ and beyond
2012
Jakob Zinsstag | Andrea Meisser | Esther Schelling | Bassirou Bonfoh | Marcel Tanner
We first review historic and conceptual background to integrative thinking in medicine. Lacking a general theory of ‘One Health’, we provide an operational definition of ‘One Health’ and its leverage as: any added value in terms of human and animal health, financial savings or environmental benefit from closer cooperation of human and animal health sectors at all levels of organisation. Examples of such added value of ‘One Health’ are given from the fields of health systems, nutrition and zoonoses control in Africa and Asia. ‘One Health’ must become main-stream rather than a new discipline or new association; it should just become normal that practitioners and professionals in the health, animal and environment sectors work together as closely as possible. Current and future challenges in financing clean energy, migration flows, food security and global trade further warrant rethinking of human and animal health services. A conceptual outlook relates health as an outcome of human-environment systems called ‘health in social-ecological systems’. The paper ends with an outlook on the operationalisation of ‘One Health’ and its future potential, specifically also in industrialised countries.
显示更多 [+] 显示较少 [-]Detection of <i>Haemophilus parasuis</i> isolates from South China by loop-mediated isothermal amplification and isolate characterisation
2012
Jian-min Zhang | Hai-yan Shen | Ming Liao | Tao Ren | Li-li Guo | Cheng-gang Xu | Sai-xiang Feng | Hui-ying Fan | Jing-yi Li | Ji-dang Chen | Bin Zhang
Haemophilus parasuis is the etiological agent of Glässer’s disease, which is characterised by fibrinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. In this study, a loop-mediated isothermal amplification (LAMP) test was developed to improve the specificity, facility and speed of diagnosis of H. parasuis isolates. The LAMP assay rapidly amplified the target gene within 50 min incubation at 63 °C in a laboratory water bath. The LAMP amplicon could be visualised directly in the reaction tubes following the addition of SYBR Green I dye. The detection limit of this LAMP method was 10 CFU/mL, which was 10 times more sensitive than the earlier 16S rRNA polymerase chain reaction (PCR) test conducted by Oliveira, Galina and Pijoan (2001), and no cross-reactivity was observed from other non-H. parasuis strains. This LAMP test was evaluated further on 187 clinical specimens from pigs suspected of being infected with H. parasuis. Forty-three were found positive by bacterial isolation of H. parasuis, as well as by the 16S rRNA PCR and LAMP tests. The 43 H. parasuis isolates were classified into 9 serovars and had 37 genetic patterns when analysed by pulsed-field gel electrophoresis (PFGE). This displayed that various H. parasuis serovars and genotypes were widely distributed in South China. Therefore, the speed, specificity and sensitivity of the LAMP test, the lack of a need for expensive equipment, and the visual readout showed great potential for a correct clinical diagnosis of H. parasuis in favour of controlling Glässer’s disease.
显示更多 [+] 显示较少 [-]Human cystic echinococcosis in South Africa
2012
Benjamin Mogoye | Colin N. Menezes | Martin P. Grobusch | Kerstin Wahlers | John Frean
Cystic echinococcosis (CE) is caused by the tapeworm, Echinococcus granulosus. The tapeworms resides in the small intestines of canids and the lifecycle involves both intermediate and definitive hosts. Humans are accidental intermediate hosts. Cystic echinococcosis is an economically important infection constituting a threat to public health, and is considered an emerging disease around the world. There are at least 10 Echinococcus strain types (G1 – G10), each exhibiting diversity of morphology, development and host range. The epidemiology of CE is poorly understood in South Africa. A retrospective data analysis of the National Health Laboratory Service (NHLS) laboratory information system on echinococcosis serology, microscopy and histopathology results in eight provinces (excluding KwaZula-Natal) showed an overall positivity rate in submitted diagnostic samples of 17.0% (1056/6211), with the Eastern Cape (30.4%), North West (19.0%) and Northern Cape (18.0%) provinces showing highest rates. The data showed considerable variability between provinces. The review also showed that most proven cases were negative on serology, implying that the actual number of patients could be underestimated. To our knowledge, no data exist about the prevalent strains of E. granulosus and this prospective study will attempt to fill that gap. The aim is to genotype strains causing the disease in South Africa. Two different polymerase chain reaction (PCR) methods will be used to respectively target the 12S rRNA and nad 1 genes. To date, three samples have been genotyped as G1, G5 and G6; suggesting diversity of strains prevalent in the country, but more data is needed for a clearer picture.
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